The research aims at collecting basic data with the participation of farmers in the Mekong Delta – Viet Nam; then proposes solutions to enhance farmers' capability in bio-diversity management, which help ensure household food security for the furture. Also in the research, the group of researchers has focused on agricultural manufacturing efficiency, food security and plant diversity at household level. The PRA - Participatory Rural Appraisal and Questionnaires menthod were used in this research. The result of research showed that the main resource of farmers' income within is from grain rice production, accounted for 95.2% in An Giang province, 74.4% in Hau Giang province and 87.9% in Soc Trang province. The division of labor in terms of gender is relatively reasonable. It has also found out that farmers have considerable knowledge of household food security; that plant diversity is decreasing as agricultural products are subjected to change towards market needs (24.3% in An Giang province, 27.1% in Hau Giang province and 33.3% in Soc Trang province). Besides, the research results also showed the fact of food insecurity and how households to react in case of food insecurity.